Telephone system



March 16 ,1926. 1,577,051

' W. P. ALBERT TELEPHONE SYSTEM Filed Oct. 29, 1920 5 t t g /WM My March 16 19 26.

W. P. ALBERT TELEPHONE SYSTEM Filed Oct. 29, 1920 S sheets sheet 5 ai Zia 3;: v w f.

1 N ,mfi W W 4. Q n m n A I 0 o o W 0 0 M Q? BM M In n mww NM P R W M W O. E v m M w 10 A w t o H C P N O D d w m m E 3w 8 u w u h 1 Mk 1 h N v m M wwh Patented Mar. 16, 1.926.

WALTER r. ALBERT, or nAsronAN-en, NEW snnsny,nss'tenon 'ro WESTERN Ema-- TRIC COMPANY, INCORPORATED, or new ong, v, .Y., A CORPORATION on NEW YORK.

Application 7'0 all whom it may concern:

Be it li nownthatl, lVALTER PLALBERT, a citizen of the United States, residing at East Orange, in the county of Essex, State of New Jersey, have invented certain new and useful Improvements 111 Telephone Systems, of which the following is a full, clear,

concise, and exact description.

This invention relates to telephone sys-' tems'and particularly to systems of the class employing automatic switches-for setting up These switchesarecapable of making rapid selections from large trunk or line groups pern'iitting, thereby, efficiency in the opera tion of equipment installed and a inarked saving in time. To control the several. selective movements of the switches in accordance with. the revcrtive impulse principle, controlling mechanisms, such as the 'Wellknown register senders, are provided at the central office. The function of the register sender is to receive the record of the desired call, and to'thereupon control the selective switches in correspondence with the registered designation to extend a connection to the wanted line or olfice. systems where the calls are first received by,

.or are communicated to, an operator the record is set up on the registers by means of a kevboard,manipulated by the operator. In offices that are provided,however, with switches alone for performing the necessary extension of the calling lines the record for determining the selective operations must he produced on the central O'iilCG' sender by means of impulses transmitted over the" line from the calling substation or, perhaps,

from distant operators positions.

The complete designation or number relating-to particular call maybe considered In seii'ii-auton'iatic selective movement of switches TELEPHONE svs'rnm. Y

filed October 29, 1920. "Serial No. 420,418;

that contains the' called line.

oflice. The first part, orthe otiice code as it may be C1ll6d,l$ recorded on thesender in the oflice ot the calling line and deter mines the selective movement of switches in that'otlice to select a trunk leading tot-he outlying Office. identified by the-recorded code. Thereafter, the sender controls switches or other devices in the distant oilice in correspondence with the numerical or second part of the designation to cause the further extension of the connection. In some cases the number of outlying offices that a. given oiticeis called upon to serve is large. I The sender in such oiiice accordingly, must be capable of recording a large number of o'liicedesignations." In order that the requisite number of ofiice'oodes may be registered"tojdeterinine"the routing of con- 'nections to outlyingibl'lices, and to care for the variousclasses of: calls involved, and to secure. a flexible arrangement whereby these. routingsina'ybe alteredirom time to time without the necessity of erqpensive and complexwiring changes, aswitch, similar in many respects to the usual selector, is provided to record the office registrations.

:Theobject of the inventionis, therefore,"

to Dl'OVlClG, in a systcn'i of the above described characterfa switch having a plurality of moven'ients, each moveinentcaused impulses sent over a calling line, to register a desired designation'to control the to'a set position for controlling the selective operation of automatic switches for extend mg telephone connections.

Other a l further features contemplated by the presentinvention will become obvione from a consideration of the following description. h I

Referring. to the drawing Figs. 1, 2 and 3 when taken in order tromlet't to right with Fig. t beneath Fig. 2 and Fig. 5 at the right of Fig. cillustrate a portion of the circuits and apparatus of a telephone oilicc h g The second [part is the number of the called line in the for extendin which the present invention is contained. In Fig. 1 is shown a calling subscriber's line terminating 1n an 1nd1v1dual line switch adapted to entend. the line. to. an. idle, trunle circuit.

Fig. 2 illustrates a trunk circuit accessible to the individual line switch and which terminates in 'a' first or district selector switch. This figure also showsa step by step sender selector switch for associating the circuits of the district switch with one of a plurality of registeig. senderhinechainisms.

' 3 shows a, second: or, ottice selector switch accessibleto thedistrictswitchl and whichserves to e; ;te nd. thecallingline over trunl s to. otherswitches either in the same.

or. in. distant oiricesj F g. 411llustrates a sender.andcontrolhng mechanism arrangedgto receive series of im pulsestransmitted over a. callingsubscribersline to, record-the oilice and numericaldeis, ignat ofn o fa called-subscribers line and to controlthe automatic-switches forthe purpose o'tiextenjdi-ng arionnectioninaccordance with theregistered designation, This-figure also illustratesa class switch, the -function of whichis to; govern the sendingmechanism in accordance with the class of the call recorded.

Fig. movement.steprby-step switch arranged to be possitioned directly by impulses from the callingsubscribers line to determine the routing oi the connection to. the proper ofpatent to Craft and Reynolds, 1,123,696, is

sued January 5, 1915.

The sequenceswit-ches 210. 310, 410 and l i-0 are the same in structure and principle as the one illustrated in detail in the patentto Reynolds and :Baldwin, 1,127,808,; patented February .9, 191:1 The sequence switches 210 and 310 control respectively ihe contactsshown in Figs. Qand 3. In Fig.

1- however the senderso uence switch etiOi governs all contactswshown. in the space above and to the right of the broken'line, while the class seqnence'switch .410 controls the ijeniiaining contacts.

In the lower part of Fig. 4 a small stepby-step switch-is shownhaving five brushes 411, 112, 413-, 11-l; and $15, each cooperating shows diagrannnatically a two.

This figure also shows a, plurality of switches on wh ch the numerical designation with a circular row of terminals. This switch performs the necessary change-over functions for associating the impulse circuit in succession with the switch and registers shownin Fig. 5. The brushes 411, 412, 413, etc. of the control switch are advanced from position toposition by means of the stepping magnet. 4116, which is. designed to step said brushes forward upon deenergization.

In the upper part of Fig. 5 are shown in a diagrammatic manner the brushes and terminal hank oi a. two motion ,step-by-step selector switch, which will be called hereinafter a translator switch. The translator comprises an ordinary step--by-step switch havingaprimary. vertical moven'lent and a secondary rotary movement with certain modifications in=the arrangementot the terminahbanl; to .suit the.- purposes for which it is employed. As illustrated, the terminal bank is divided intosixdirterent sections, 505,, 506," 50?, 508', 509', and-'5l0;=- Each 01 these, sections. hasten levelsot ten terminals,- comprising inall onehu-ndred terminals. Cooperating with each section of one hundred terminals is. a brush, such as 511,

513, ete. Z'hese brushes are all mounted on the, same shaft andoperated vertically by a magnetcOi and in thcrotary movement-by stepping magnet-503. In addition to the. six sections of one hundred tern'iinals, the swi ch is provided with a vertical row oi ten terminals 517. Brush 518 contacts. with these.terminalsduring the pri mary movement or" the switch and is ranged to disengage the corresponding. term nal when the switch is stepped in its rotarymovement over a given level. The severalcontacts of the bank are connected to contacts, such as 4'52 and 173 of the class sequence.switch410. By thus connecting the terminals of this bank to contacts of the class sequence switch; said sequence switch may hev caused to take up positions in accordance with the level and tern'iinal in the level selected by the translator switch'under the control of impulses sent from the callinn subscribers substation. The first two series of impulses cause the setting of the translator switch, identifying the particular o rice to which the connection going to be extended. rrccording to i which connections are handled in the called otlice, "as, tor; GFZE'ZDU JlB, in. tullniechanical or semi-mechanical' manner, the class sequence switch 410 takes up a setting to grovern the operation of the sender in controlling the extension of the particular connection involved. Some of the outlying oiiices served through the otlice shown in the drawing will he provided with switches for han dling; incon'iing calls on a full mechanical basis; Calls to these oliices cons. itute one class. Again other ofilceswill be equipped with callzindicators at an operators position the manner in for completing the connections manually. These offices will constitute anotherclass. Similarly tl ere may be several other classes of calls that will have to be taken care of. For this purpose the class sequence switch H isprovided and is variably set, as will hereinafter be explained in detail, in accordauce with the terminal on which the brush 511 is positioned. One position of the class required.

sequence switch will be assigned for full mechanical calls, another position for call iiidicator calls, etc. In order that the class sequence switch may take up the proper setting, it only becomes necessary to connect the terminals of the bank 505 to contacts 472, 4-73, etc.iii their different closing positions in such a manner that, When the brush 511 is positioned on a particular terminal under the control of impulses sent from a calling subscriber representing the code or" an otlice relating to a given class of calls, the class sequence switch is driven to the corre sponding position.

The terminals of the bank 506 of the translator switch are connected arbitrarily to the diilerent counting relays of the sender shown in Fig. 4-, such that when brush 512 is set on a given one of the one hundred terminals a circuit is extended tothe proper point in the series of counting relays to control the selectionyof the necessary set of brushes of the district switch. Similarly the section 501 or the terminal bank has its terminals wired to the counting relays tor controllingdistrict group selection, and the terminals of banks 508 and 509 are likewise wired to the counting relays l orcontrolling office brush and ollice. group selections respectively. Fromthis explanation it will be observed that a hundred different con'ihinations may be. secured by wiring the hundred terminals of the four sections 500, v

507, 508 and'509, to different ones of the ten counting relays. The firsttwo series of impulses sent by the subscriber to position the translator switch determine the district brush, district group, office brush and. oli'lce ,sr ioup selections to select a trunk, such as trunk 1328, 329 leading to the ofiice containing the called line. Iiiother woros the first two letters, or numerals identii'ying the called ofiice deterii'iine the vertical and rotary movements of. the translator switch for the purpose of selecting this oliice. In order, therefore, to make changes in the codes and routines whenever the sume becomes necessary, all that need be done. is to change the manner in which the terminals of the translator bank are wired to the counting relays. 'llhetranslator switch is illustrated as hav- 0 ing sixsectioiis in the terminal bank. i hile the last section 510 is not utilized in the. present system, it may serve for any desired purpose where more than five brushes are In the lower part of Fig. 5 the numerical registers 5 10, 5 15, 550 and are diagrammatically illustrated. These registers each consist of a rotary step-by-step switch hav ing a plurality oi brushes and cooperating terminal banks and za-ch is propelled in a st,epby-step movement by the respective stepping magnets S ll, 5&6, 551 audio-56. Following the transmission of the first two series of impulses for setting the translator switch, the subscriber sends tour series oi impulses identifying the digits of the called BR8111111111361 which cause the variable setting of the numerical regsters, The banks cot each oi these registers maybe wired. in any convenient manner to the counting relays in order to control incoming and final switches or call indicators either in the local ofiice or in a distant otlice selected by the district and oliice switches illustrated in 2 and 3. Inasmuch as the present invention relates more particularly to the translator switch and the manner of controlhi the same over the calling line, it is not found necessary to illustrate and describe the coutrolling mechanism in further detail nor to I show the diiier-ent types of appara us that may be installed in distant called oliicesf For a more extensive explanation of u res-R ister sendero't this typere'lerence is made to the above mentioned Patent No. 1,395,077,

issued to Stearn and Scudder. 7

. Having given a general explanation o": the system it is believeda' better understandinc may now behadjot the nature of the inven? tion by describing in detail the operations concerned in the extens on of a connection.

F or this purpose it will'b'e assumed that the i subscriber of line 100 desires to converse with a subscriber whose line terminates in an oflice identified by thecode N0. 37. In

practice it is probably more convenient to identify the otfices by letter codes which back contact and inner lower aii'nature or relay v104, over the loop oilhe callingstation 100, tog-round at the upper armature and back conta'rt of relay 104. li'elay 10 becomes energized and completes a circuit from battery through the winding or step ping .inagn'et 105, arn'iatiiire and contact ot said magnet, lowermost armature and contact ofrelay 10s, right-hand armature and front contactot' relay 103 to ground through thebrush 1 11 and terminal 114. 'Magnet' 105 energizes, interrupts its own circuit, dc-

energizes, and steps the brushes 100, 107, 108, 109, 110 and 111 forward one step. Brush 109 thereupon engages the segment 113 and battery potential is supplied to the test terminal 102 of the calling line 100 in the multiple banks of all final selector switches lr ring access to this line, In this manner the calling line rendered busy T he ahore traced circuit is again completed for r nct 105 by way of brush 111 and terminal 119, and the switch continues to the next set otyterniinals which represent the ti ota plurality of trunk circuits leading to district selector switches. So long as the individual switch encountersthe ternii- 112115 of busy trunkshrush 111 linds a ound potential on the test terminals 120 such trunks and the switch continues to rotate. i't'hcn the first idle trunlt115, 116

is reached no grouiidpotential is. present on 191111 111211 120 and, consequently; the ste iiiag'net 105 ceases to adv-aucethe sw Since the trunk 115.110 is idle, sequence switch 210 01 the district switch associated with such trunk is standing in position 1. A circuit is then closed from battery through Contact 203 (1.), hack con tact and lettwhand armature ot relay200, conductor 118, terminal 120, brush 111.com tact and left-hand armature audle'tt-haiid pping' the winding of relay 103, through both Winding};

of relay 10:1, in series, to ground. Relay 10-1 becomes energized in this circuit and locks -.-up in circuit as follows: battery, through .hand arn'iature of relay 200.

completes a circuit from battery through the right-hand winding; of relay 212, lower left-hand contact 21 1 (1),.rightd1and contact 208 (1+10), left-hand contact 208 (1+3), to ground at the coiitact and right- Eelay 212 becomes energized and closes a circuit from battery through the winding of sequence switch magnet 210, left-hand contact 215 (1), front contact and right-hand armature of relay 212, lower contact .13 (1+6), to Sequence switch 210 advances from ground. position 1 to position 2. A circuit 1911011" closed from ground over upper left-hand contact 209 (2+18 conductor 118 to.

'niultiples of terminal 120 to holdthe trunk busy. Should the test brush 24101 the sender selector switch chance to be. standing on theter ninals of a busy sender atthis time, relay 207 ofsoiiie other switch isenergized, as will be later explained, and acircuit is provided for maintaining the operation of relay 212. This circuit may be traced from battery tlirou h the left-handwinding and contact and lert-hand armature otrelay 21-2, upper lett liand contact 251 (1+6), lower contact 220 (1+ 2- /i conductor 252, brush 2 11, thence over the multiple oi the test terminal individual totlie busy sender, to the brush 211 of the sender selector that is rendering said. sender bu toground a; the inner left-hand,armature otthc opcrat d relay corresponding to the relay 20?, shown in the figure. Relay 212 ren ains energized in position2 of sequence switch 210, and, in so doing, provides a circuit for the stepping magnet 211 for advancing the, brushes 239, 210, 211, 212, 253, and f 211, of the sender selector switch shown, to searchfor the teri'ninalsoi an idle sender. The circuit for magnet 211 may be followed from battery through the contact and armature and winding; of said inagi'iet, conductor 253, left-hand contact 218 (1' +2), trout contact and right-hand armature of relay 212, lower contact- 213 (1+0), to ground. At the same time a circuit is maintained 1110111 battery through the contact and a-rn iature andwinding'ot niagiiet 211, through the winding 0t relay 207, to ground at the lower left-hand Contact 209 (2+11). Due, however,- to the shunt provided by the above traced circuit, sufiicient current does not flow through the winding ot relay 20. to energize the latter. Stepping magnet 211 interrupts its own circuit and advances the brushes of the sender selector in a stepby-step movement to search for an idle register sender. When the .tirst idle sender is reached, relay 212,becomes ClGBHGIgiZECl since no ground potential is found on the multiple terininalengaged by the test brush 211. Relayv 212 opens the direct circuit to ground for the magnet 211. Magnet 211 is now included in series with relay 207, and this relav attracts its armatures. The iuagiiet-211 does notcontinue to operate in view of the high resistance of relay 207. Relay 207, at its inner left-hand armature, applies aground potential to the test terminal torender the selected sender busy to other sender selector switches. lelay 212, on retractingits arinatures, 00111 pletes a circuit as follows for drivingthe sequenceswitclr 210 out, of position 2 and into position 3: battery, through the winding of said sequence switch, right-hand contact 215 (2),oacl: COntEICtiUTCl riglit liand: armature of relay212, lowercoiitact 213 (1+6), to ground. Relay 207 also closes a circuittroin ground over its inner lefthand armature brush 211. contacts of the class se uence switch 410 windin O1 relay 402 to battery and ground. Relay 402 locks up over its inner armature and at 1ts outer armature closes a circuit byway of upper left-hand contact 408 for driving be traced from battery throu h the wind- 0 ing of impulse relay 400, brush 240, outer left-handarmature and contactof relay 207, lower contact .301' (2+101/ conductor V1.1(i,term inal 122, brush 108, front contact and inner lower, armature of f relay 104, through the loop of substation 100, upper armatureand front contact of relay 104, brush 100,terminal123, conductor 115, lefta circuit over its armature and. front contact for the slow to release relay 404. Relay 404 closes acircult from ground through its outerleft-handarmatureand contact,

conductor 425, verticallofl normal contact 531, winding of relay 500 to battery andground. Contact 531 is controlled by the shaft of the translator switch and 1s closed dru'ingthe time said shaft is inits normal trol switch, to ground. Current flowing in this circuit induces a current in the righthand n'inding of the co1l401,wh1oh is transmittedoverthe impulse circuit above traced,

to produce a characteristic sound in the call .ing suhscribers receiver. This sound indicates that a sender has been assoc1ated wlth the calling line and that theisubscriber may proceed to transmitimpulses.

Tl? he subscriber thereupon operates the sendingdial 101 to transmit the first digit 2- of the code identifying the office in which the called line appears. The firstinterrup tion ot' the impulsecircuit causes the de- .the 'w-indingof relay 406, brush 41-3, terminal 433', conductor-422, contact and outer unease armature of relay 500, conductor "ation of relay 400, which completes 560, contact and armature of magnet 504, conductor 559, front contact and inner right-hand armature of relay-500, conductor terminal 417, brush 412, Winding of relay 405, front contact and right-hand armature of relay 404 to ground at the back contact and armature of relay 400. Relay 406 1 u 'I 080011168 energized and, completes a. circuit from ground through its outer armatureand contact, Winding of 'relay 405, brush 412, terminal 417, conductor 424, and thence, as

above traced, through thewinding of magnet 504 to battery and groundfi Relay 400 15, therefore, energ zed in a circuitwhich depends upon the armature and contact of the verticalstepping magnet 504, andas long as. itv remains energized a circuit foiv said magnetns maintained independently p I of the armature and back..contact of relay hand, contact 200 (24-10%), brush 239,." V L righthand winding of coil 401, to ground. lF lelay400 becomes energized and completes consequent attractionof the armature of res lay 400 does not cause the premature opening, of the circuit of the stepping magne 504. The magnet 504 reniains'energized, depenclingupon the relay 406, until it'has had time to advance the brushes of the switch a full step toposition them op posltethe first levels of terminals When the full step has been completed the armature and contact of relay 504 are opened andthe circuit of relay 406 is'interrupted. Relay 406thereupon releases its armatures and opens the circuit of the magnet 504, which in turn. becomes deenergized." Itelay 406,furthe rmore, maintains a circuit at ts nner armature and contact for'the slow to release relay 404. Relay 404 is designed to remain operated during the normal. periods in which'lts circu t is opened by the armature of relay 400.

If, howcveiw relay 400 remains decnerglzed for an exceedingly long period, relay 404; cannot become deenergized due to the fact that relay 406 provides a substitute holding circuit therefor.

;As the translator switch takes its first step, thecontact531' is opened to interrupt the original energizing circuit of relay 500. Relay 500, however, remains energized in a circuit. as follows: battery, through the winding "and front contact and inner lefthandarmature of relay 500, conductor 42$,

contact and armatureof the slowto release relay 405,130 ground. Relay 405, be1ng of the slow-to-release character, doesnot retract its armature during the brief interrup tions of its circuit at the armature and back contact of the stepping relay 400. 'On each of the following interruptions of the line circuit in the transmission of the first digit,

the brushes 511, 512, 513, 514, 515 and 516 .of the translatorswitch are advanced one stepuntil they are finally posltion'ed opposite the third levels of terminals in their respective banks. Following the third imoised had pulse, the steppingrelay lOO remeinsencrgrize'd for a comparatively long period, during rlnch interval. the SlQflEtO-TQlGElEQTG- ley 405 isipermitted to release its armature. ltchrv e05 ooens. the holdun circuit t rela v v U I L A7 n00, Winch becomes deenergized. 1

ihe calling SHlJSCIllJQf. nest operates the sending dial 101 to transmit a series ot seven impulses representing the second digit of the oiiico code. On the first opening of the impulse circuit, relay, 4900 .hecomes 'deenercorimletcs a circuit: rom ground ig'h its armature and back contact,

hand armature andxiront contact'of windi of relay 4-0-5, brush 4:12, 131211 1417, conductor -24, inner righthzznc armature and back contact of relay 500, corductor 561,.nfinding of the rotary stepping; iilzzgnet to battery and ground.

circuit is zilsoclosed for the energizetion of relay 4:00 as follows: battery, through the windmg of said relay, brush Cil. hes of the translator srqitch 29:

ed one step over the third levels 0 teiilfitliltl arefinzilly iroug'htto rest i'r engagzement with the seventh terminals 52; and The sloW-to-release relay 4:05, which also becomes energized during the transn'iission of the second ties of impulses, completes a circuit from gromd through its armature and contactc-oiiductsrf-jil, inner-letthand arn'mture and hzatl; contact of hi 500, conductor 1- 7, Winding oil the ste ping magnet 210 to bittm-v ground. Magnet -l16 energizes 21 ill t inepziretoij to advancing the brushes oil-the cor trol switch when its circuit-is opened. r the lust impulse has been transmitted, 00 r mains energized for a p riod of -ient to permit the released the "05. Relay 405 open-stirs circuit energizc sanded' sth ll 12,

*13 14: and Meir second po' on The two movement step-by-Step selective switcl has thus been positioned in accord- '-.th the ofiicecode to dete1.'n""e the district and-'otiice hitches call in the proper direction. t .ihscriher continues to manipu- I to t'ansmit the;digits corresponding to'the numericaldesignation ot the of stepping magnet to hatte ceived.

vented line. In :1 ten thousand line ofiicc thesubscrihefs line numbers consist otfonr digits and consequently four numeric-(1i reg;- rs, &0, 54?), W0 and are provided to the :1 record 0r these numbers. When the dial 101 isoper-rted to transmit the first digit of the minted nrm'iher, relay 400 hc comes deenerg'ized and completes a circuit from ground through. its arn'iaturc and back contact, right-hand armature and front con tact of relay 4:01 winding of relay 4e05, brush 4:12, terminal 118, conductor ll-29, winding ry and ground.- Wagnet 541 energizes and Lipon its circuit being broken at the end of tie first in'ipulsendmnces the brushes 5&2, 5 13 etc. to the first position termii'mls. In a similar manner, for each succeeding impulse in the series, the brushes otregister 5-H) are udmnced ste1)-l3y -step imtil at position correspending-to the first digit is ""1CllCl. Relay 105 completes the circuit above traced for the stepping magnet 416, and at the end of the series this relay releases to permit the decnergizetion ofsaid magnet. The l rushes llL'dlidlEi, etc. ofthe control switch are at winced to their third position tern'iinnls.

The energizetion of relay 400 in response to the transmission oft-l e secont series of impulses 'oi the Wantedlinc number causes a circuit to'he closed from ground through the armature and front contact of relay windingzot' rel-d3 e05, brush e119 terminal 5H9, con Pieter-2430, winding of steppingma ;ll' iground; moved the'regishe is iereupoii forward stcp-by-stcp in rcsponsd to the scond series of impuls s. Relay 40s closes the shore traced circuit for '7 ping nnignet zmdnt the end opens this circuit t pcrnr switch to adrn'nce'to ie'fourth osition.

, :1 sh-nihir .n' miner the next :{nd last two "s of im' nilscs'm'e dircctcl to the stepping magnets Stand or the registers 550 and 555respectirily, em th i r:

the up their correspo':idins he transmission of el ctions 11 tic l hile tl e -d1'strict switches are "be ng and om positioned the subscribe (1 continue the dial'ng operation. to rec the mi 'of'the cr'lledlinen' k 'ator switch has lriznediatcl that the trans been positioned, the control-switch is moved to its seccn-tl position terminals as explained. rrcircnit is then closed from battery through the Winding-of relay .0"? ,terminal 435,- brush el l to -gronndf Relay becomesenergizednet Set )Of the next register, 0 better y and locks up in a circuit from battery through the winding and'outer armature and contact of said. relay,- upper contact 4'74 (l +18) ofthe class sequence switch 410 to ground. It will be recalled the sequence switch 410 is standing in position 3. Relay 407 completes a circuit from groundthrough its inner armatureand contact, let't-hand armature and back cont-act of relay 4T1,

lower right hand contact .408 (EH-15), wind-. ng of sequence switch magnet 10, to batvtcry and ground; Sequence switch 410 is energized in this circuit and commences to rotate to take up the position corresponding to the class of the call that is being made by.

the calling subscriber. Said sequence switch will rotate as long as relay 4T1 remains dcener-gized and th s relay will only become energized when the particular one of contacts 472, 473, etc, corresponding to the position which the translator switch has taken, is

closed. In the present instance it is assumed that position 10 of sequenceswitch 410 repre sents the class of the callzunder consideratron. lVhem'therefore, sequence switch 410 reaches position 10, a circuit is completed from battery through the winding of relay 47 1, upper right-hand contact 472 (94-101,

conductor 476, terminal 522,-brush 511 to.

ground. #Relay 471 bec'om'es energized and locks up in a circuit from battery through its winding f and right-hand armature and contact, lowerconta'ct 474 (44-17) to ground.

Relay 471, at its left-hand armature and haclrcontact,opens the above traced circuit of sequence switch 410 and this sequence switch comes to rest in position 10. Further more, relay 471*completesa circuit for ad *ancing the sender sequence switch 440 out of position-1 and into position 2. This circuit may be traced from battery through the winding of the magnet of sequence switch 440, upper right-hand contact 439 (1), front v contact and left-hand armature of relay 471, 1 contact and inner armature I to ground.

of relay 407 *With thesender seque-nce switchin position 2, thefiiiuidamental circuit is closed as followsto control the selection of the proper set of brushes at the district switch: hats. 'tery, through the left-hand winding 01 rc lay 212, upper right-hand contact 251 (3), lower lettshand contact 251 (3+6), contact and right-hand armature of relay 207, brush 242, contact 447 (4+13 c0ntac't 443 (2), winding of the stepping relay 445, armature and contact of relay 466, contact 444 (2) to ground. Relay 212-beco1nes energized and completes a circuit frombattery through the winding of sequence switch magnet 210, lefthand contact 215 (3), front contact and right-hand arn'iature o'f rela-y 212, lower contact 213 (1+6) to ground. Sequence switch 210 advances from position 3 intoposition In position 4, relay 212 remains energized in a circuit from battery through the left-hand winding, contact and left-hand armature otsaid relay, upper leit-hand contact (1+6), lowerleft-hand contact 251' (3+6) and thcnceto ground, as described, over the fundamental circuit. Belay 212 completes a circuit: for the updrive power magnet 4 to cause the upward movement the brush shaft 248. I be traced from battery through the winding of power magnet 224,.right-han-d contact 218 (4), front contact and rightdiand armature of relay 212, to ground at t-he lower con tact ins.

I I The steppin grelay 445, which also ener gizes inseries w th relay 212, completes a circuit froinground through its armature and contact, upper contact 465 (2), conductor 469, brush 512,0fthe translator s VltCll,

terminal 523, cont actor 527, and thence, to conductor 455, F1g. 4, armature andback contact of relay 449, winding of relay 450 'tosbattery-and ground. Relay450 becomes energized and completes a circuit for itself series with relay-449 as follows: battery,

through the windings of relays 450 and 449,

ment'of commutator 230 andfa circuit is closed as follows: battery, through theleithand wind ng and Contact and left-hand armature oi relay 212, upperlett-hrhid con-- tact 251 (1+6), upper contact 220 (3%+ 4), commutator 230, brush 228, contact 22.3- (9-1-7) to ground; Relay 212 remains en ergized' in this circuit and the stepping relay; 445 in thefundainental circuit 1s shuntedout. Relay 445 deenergizes and remoyes the shunt from around the winding 1 of the counting relay449, permitting this latter" relayto energize in serieswith relay 450. The brush shaft 248 continues to. ad-' Vance andbrush 228, engragingthe nextin sulatingsegment. permits the'cnergization I of relay 445. The stepping circuit is new extended by \\='ay' it conductor to the armature and front contact of relay 449,.

armature and backcontact of relay 451,

,winding of relay 452 to battery and ground. Y in a ike manner for each brush tripping;

position approached by thehrusl snail. 248 a pair of counting relays are energized and locked up until finally the No'Oicounting relay 454 becomes energized. Relay closes a holding; circuit for itself in series parallel with the windings o1 relays 453 and 466. This circuit may be traced from ltat'ter throu 'h the wlndin of rela i454.

-wh =ncefit divides, one branch leading- This circuit may Amt i (it) lit) to Contact at the through the winding of relay 45s and the other branch" leading through the winding.- of relay 466, and thence to the contact and armature o1 relay lower contact-463 (2) to ground. As thebrush 228 encounters the neXt metallic segment following the energization of relay 4.54, the" stepping relay deencrgizesand permits the operation of relayselSS and 466. Relay 466 opens the fundzunei cal circuit, and relay completes a circuit from ground through its. armature and contact, contact M1 (2), winding of the in gnei; of the sequence switch at-lO to battery and ground. Eequence switch AO advances out of position 2 and into position i. As sequence switch +l-l leares position 2, the lower and upper contacts 468 are opened to permit the release of all counting relays that have been energized.

As seen, following the opening of the tzuulamental circuit at the sender, as brush 228 engages an: insulating segment of corninutator 230, relay 212 releases its armatures and opens the circuit of the updrire J- O v l 1' power magnevu 22st, causing Elle. b1 ash snart 2. .8 to come to'rest. Relay 212 also coinpletes a circuit from battery through the winding of sequence switch magnet 210, right-hand contact 215 l) back contact and i-ight'diand arm'atureof relay 212, to ground at the lower contact 213 (1+6). Sequence switch 210 thereupon advances into position 5. In this position a circuit is closed from battery through the winding of trip magnet 225, contact 221 (+6) to ground. Magnet 225 becomes energized and rotates the trip spindle preparatory to tripping the selected set of brushes upon the next upward movement of the brush shaft 2-l8.

\Vi'tli the sequence switch 210 in position 5 and the sender sequence switch &0 in position 4, the fundam ntal circuit is agz-iin closed to control group selection at thedistrictswitch. This circuit corresponds to the one hereinbet'ore traced with the exceptier; that the contacts of sequence switches 210 and lit) are close-cl in ditierent positions. Relay 212, upon energizing in the fundamental circuit, closes a circuit for driving sequence switch 210 out of position 5 and into position 6. This circuit leads from battery through the winding of the magnet of said sequence switch, leit-hand-contact 215 (5), front contact and right-hand armature of relay 212, lower contact 213 (1+6) to ground. Relay 212 remains energized in position 6 of sequence switch 210 by'ineans of the locking circuit from battery through its left-hand winding and contact and lefthand armature, upper left-hand contact 215 (1+6), lower leitt-l'iand contact 215 (3+6) iiundamentalfoircuit as described. Relay 212 again closes the circuit for the up'jdrive power magnet 22% overthe right-handcontact 218, closed in position 6,

Brush shalt-2&8 is advanced and brushes 233, 23st and 285 are tripped into engagement with the terminals of the bank.

The stepping relay ll-5, which also onergizes in the fundamental circuit, conr pletes a circuit "from ground tlnoug'h its armature and contact, lower contact il- (a), conductor l-QO, brush 513, terminal 52 1:, conductor thence to conductor e57, Fi 4:, armature and back contact'ot t1 counting relay 4e61, winding of the counting relay to battery and groi. Relay hi2 becomes energized and prepares a series holding circuit tor itselfand relay its the brush shaft approaches the stir) 'rou'i of terminals, brush engages the first metallic segment of commutator 231, and a. circuit isclosed from battery through the lefth'and winding and contact and left-hand arn'iatur of relay 212, upper left-hand contact 251(1-1-6), lower righthand contact 251 +6 commutator 231, brush 227, COltftCl] (9"?) to ground. llelay remains energized and the stepping relay t'll; is shr ted out. Relay 4%?) dccnergizes ant. permits the energization of relay 461 in series with relay -l62. In a like manner, succeeding pairs otcounting relays are energized and up and the brushes 283, and 23 pass over succeedinggroups of terminals. The 0 countin relays 4:5 1, 453 and l66- are finally energized and the fundamental circuit is opener.

lay e53 closes a circuit including contact (at) for driving the sender sequence switch rule sequence switch ll-0 leayesposition 4, the contacts are opened and the energized counting; relays release their armatures.

As'soon, following the opening 01 the fundamental circuit at the armature and contact relay :56, as brush 22-7 encounters an insulating segment of the con'nnutator 2931, relay becomes deenergizcd and opens the circuit of the updriwe power magnet 22%. Relay 212 also closes circuit from battery through the winding of sequence switch magnet 210, right-hand contact 215 (6), back contact and right-hand armature of relay 212, lower contact 213 ground. Sequence switch 21!) thereby ad yances from position (3 into position 7. With the district sequence switch 21-0 in position 7, a circuit is immediately closed from battery through the 1'' hand winding of relay 212, lower lQfL-hfllld contact -31% (2 1 7 4), upper right-hand contact 208 (l{-l0), upper lettehand contact 208 (7+8), contact and right-haud 21""51UZTO of relay to ground. Relay i112 becomes energized and conipletes a circuit from battery through the winding of sequence switch magnet 2,10, left-hand.- contact 215 (7), frontv contact and righteh-and' armature 0t out of position i and into position (3.

(1 +'18) of the class sequence switch to ground. It will be recalled the sequence 1 switch 110 is standing in position ,3; Relay aO'T'comple-tes a circuit from groundthrough its inner armature and contact, left-hand armature and back contact ot "relay 412 1,

lower right-hand contact 108 (3+15), wind ing of sequence switch magnet. etlthto bat Sequence switch 110 is tery and ground. I energized n this circuit and commei ces to rotate to take up the posit on rrespon'ding to the class of the call thatis-being made by the calling subscriber. Saidsequence switch will rotate as long as relay 171 remains deenergized andthis relay will only become en ergizedwhenthe particular one of contacts 172, 173, etc., corresponding to the position WlllClI the translator switch has talren, is

closed, In the present instance it is assumed that position 10 of sequence switch no repre-. sents the class of the. call under considera-' tion. When, therefore, sequence switch 410 reaches position 10,- a circuit is completed from battery through the'windinp' of relay 171, upper right-handcontact 4:72 (9+10), Y conductor 176, termina1'522, brush 511 to ground, Relay 4171 becomes energized and f locks'up in acircuit from battery through its w nding, and. right-hand armature and contact, lowercontact J4 (4+1?) to'ground.

Relay 471, at its left-hand armature and back contact, opens the above traced clrcuit of sequence switch 4110 alltitlUS sequence,

switch comes to rest in positionlt. "Furthermore, relay 471 completes a circuit for advancing the sender sequence switch 440 out of position 1 and into position 2. This circuit may be traced fronibattery through the contact and inner armature of relay 107 to ground.

With thesender sequence switchin position 2, the fundan'ient'al circuit isclosed as follows'to control the selection of the proper set of brushes at the district switch: battery, through the left-hand winding" of re lay 212, upper right-hand contact'2 51 lower left-hand contact 251 (3+6), contact and right-hand armature of relay 207, brush i2t2,contact 1 1? (4+13 contact 4 13 winding of the stepping relay M5, armature and contact of relay 4-66, contact 441% (2) to ground. Relay 212 becomes energized and completes a circuit from battery through the winding or" sequence sw tch magnet 210, leftinto positio1i 1. In position 1, relay 2 12 remains iting segment, perini extended '2 position approached by the brush shaft -front contact and Sequence and 466.

energised in a circuit from battery thri'iugh the left-hand winding, contact and left-hand. armatureojt said relay, upper lett-handccn- I tact 251 (1+6) lower left-hand contact 251 (3+6), and thence to ground, described,-

over the I fundamental mesa.) Relay 212 completes a c rcuit for the updrive power ma gnet' p to cause, the upward movement of the brush shaft This, circuit may be traced froinbattery through the winding of power magnet 22 1, right-hand contact 218 1), front contact and right hand armature circuit from ground. through its armature and contact,';upper contact 465'-(2),'conductor 4-69, brush 51201 the translator switch,

terminal 523, conductor 52?, andthence to "conductor ioo, Fig. 4:,armatrire andback contact of relay 4 19, winding of relay 4150 to battery and ground. Relay 150'becomes ';ei1ergized and completes a circuit for itself series with relayeafias follows: battery, t through the-windings of relays 150 and 4.49, k

preaches the first brush tripping position a brush 288 encounters the first metallic segment of commutator 280 and-a circuit is closed as follows battery, through the left-i han d winding and contact and left-hand ojtrelay 212, to ground at ti o lowerconno; 21a 1 4 j r The stepping relay 4:45, whichalso enen' o' 'zesin series with; relay 212, completes a li t) arntiature of relay212, upper. left-hand cone tact 251 (1+6), upper contact220 (3% 4), commutator- 230, brush 228, contact 223 I (9+7) to ground. winding. of the magnet of sequence switch- 4 1O,"upper right-hand contact 4139 (l), tront contact and left-hand armatureo1 relay 4-71,

Relay 212 remains en ergized in this circuit and the stepping relay 1415 in the fundamental circuit is 'shuntedout. Relay 4: 15 deenergizes and removes the shunt from around the win-ding (of the counting relay 1-419, permitting this armatiu'e andfront contactflot relay 4419, armature and back contact 'of relay 4-51, winding of relay 152 to battery and ground, In a like mannerfoi' each brush tripping itq a pair of counting relaysare en'er ized and locked up until finally the No. J0 countingrelay 4154: becomes energized. Relay-C1541 by way of conductor to the closes fa'holdingcircuit for itself in series parallel:withfthe windings of relays 453 This circ 't may be traced from battery through the windingot i relay 15st, whence diyides, one branch leading to ground. .As the brush tures through the winding of relay 1-53 anc the other branch leading through the winding of relay $66, and thence to the contact and armature'ot relay 1541, lower contact (2) 228 encounters the it metallic segment following the enercircuit from ground through its armature i contact, contact A1 (2), winding of the the sequence switch 1-10 to battery and ground. Sequence switch 4A0 advances out of position 2 and into position 4. As sequence itch are leaves position 2, the lower and upper contacts Y are opened to permit the release of all counting relays that have been energized.

is seen, following the opening out the iundainental circuit at the sender, as, brush engages an insulating segment of con. nuitator 230, ,relay212 releases its -rn1aand ope'is tl e circuit of the updrive power magnet 22%, causing the brush shaft 248 to come to rest. Relay 212 also coinpletes a circuit from battery through the winding of sequence switchinagnet 210. right-hand contact 215 hack contact and right-hand armature of relay 212, to ground at the lower contact 213 (1+6). Sequence switch 210 thereupon advances into pos tion 5. In this position a circuit isclosed trom battery through the winding of trip magnet 225, contact 221 (5+6) to ground. hlagnet 225 becomes energized and rotates the trip spindle preparatory to tripping the cte-c set of brushesupon the next upward movement of the brush shaft 2&8.

"With the sequence switch 210 in position '5 and the sender sequence switch latO in position 4-. the fundan'iental circuit is in closed to control group selection at the 'li. trict switch. This circuit corresponds to the one hereinhetore traced with the creeption that the. contacts of sequence switches 210 and i are closed in different positions. Relay 212, upon energizing in the fundamental circuit, closes a circuit for driving sequence switch 210 out of position 5 and into position 6. This circuit leads from battery through the winding; of the magnet of said sequence switch left-hand contact 215 (5) tron-t contact and right-hand armature ofrelay 212, lower contact 213 (1+6) to ground. Relay 212 remains energized iposition of sequence switch210 by means of the locking circuit from battery through its left-hand winding and-contact andletthand armature. upper left-hand contact 215 (1+6) lower left-hand contact 215 (3+6)- to contact at the tun'damcntalcircuit as described. Relay 212 again closes the circuit tor'the 'updrive power mag-net 224 over the rightdiand contact 218,, closed in posi i n Brush shaft 2&8 is advanced and brushes 233, and 235 are tripped into engagement with the terminals of the bank.

The stepping relays-l5, which also enin the fundamental circuit, coma circuit from grounc through its .re and contact, lower contact 465 1-), or 3210, hrush 51 3, terminal 52 i, conoyctor thence to conductor e57, Fi 4, armature and hacl: contact of the No. 9 con? ting relay-(EL winding of th No. 9 counting relay 1-62 to battery and ground. Relay hi2 becomes energized and pre )ares a series holding circuit tor itself and re ay +151. As the brush shat'c 2&8 approaches the hrst group oi terminals, hrush227 engages tl c lirst metallic segment of commutator O\\ not, and a. circuit is closed from battery through the le Tthand wiiding and contact and left-hand armature of relay 212 upper left-hand contact (1+6), lower righthand contact 251 (5%+6), commutator 231,

hrush 2 contact (9+?) to ground.

.al2remains energized and the stepping re -..y is shunted out. Relay nearergizes and permits the cnergization of relay 161 in series with relay 162. In a like manner, succeeding pairs of counting relays are energized and locked up and the brushes 233, 231 and 235 pass rer succeeding groups of terminals. The 0 counting relays on, 4.53 and too iinallyjenergized and the fundamental circuit is opened. Be-

lay s53 closes a circuit including contact 141 t) for driving the sender sequence switch ti out of position 1- and into position 6. as sequence switch 4A0 leaves position 4-, the gized counting relays release their armatures. 1

As seen, following the opening of the iunt amental circuit at the armature and contact relay 166, as brush 227 encounters an insulating egment or" the commutator 2311, relay 212 becomes deenergi'zed and opens the circuit of the 'updrive power inao'net Relay 212 also closes a circuit trom battery through the winding of sequence switch magnet 21, right-hand contact 215 (6) back contact and right-hand armature of relay 212, lower contac 213 (1+6) to ground. Sequen e switch yanees from pa liitll the district prized and completes a through the winding 210, front contact circuit from cattery 01 sequence switch left-hand contact 215 (T), and right-hand armature 0t contacts 163 are opened and the enerrelay 212, upper contact 213 (7+8),.rightquence switch 210 advances out of position 7 and into position 8. Relay 212 remains Operated provided the trunk in theigroup upon the terminals of which the brushes 233, 234, and 235 are standing is busy. In this case the test brush is standing on a grounded test'tern'iinal and the following circuit is closed for relay 212.: battery, throughthc left-hand winding and contact and left-hand armature of relay 212, upper left-hand contact 222 (7 +9,) upper right-handcontact 222 (7 +16), brush 235, and'then'ce to the grounded test. terminal of thebusy trunk. Itwill be noted that the upper left-handcontact 222 does not close until in position 7 Thisclosure, however, takes place prior to the opening of the original energizing circuit of relay 212, as the lower left-hand contact 214 opens when sequence switch 210 moves out of position 7 Relay remaining energized a circuit is coi'i'ipleted' for the updriye: power magnet 224 from battery through the winding of said magnet, right hand contact 213 (8), front contact. and right hand armature of relay 212, lower contact 213 (7 +16) to 1 ground. The brushshaft 243 is driven upwardly and brushes 233, 234 and 235 pass over the bank terminals to search foran idle trunk. When the first idle trunk is encountered, no ground potential being found on the test terminal 238 thereothrelay 212 becomes deenergized and opens the circuit of the updrive power magnet 224. Relay 212also closes a circuit astollows'for driving sequence switch 210 out of position 8 and into position 10: battery, through the winding of the-magnet of said sequence switch, right hand contact 215 back contact and right-hand armature of relay 212, lowercontact213 (7 +16) to ground.

\Vith sequence switch 210 in position 10,,

and the sendersequence switch 440 in position 6, the fundamental circuit I'SEAtGIKlGd through to the office switch, shown in F1 for controlling brush. selection. This circuit may be traced from battery through the right-hand winding of relay 300, lower let hand contact 306 (1), left-hand contact305 (1+4), conductor 249, terminal 236, brush 233, upper right-hand contact 246 (104-15) lower right-hand contact 246 (10), conductor 254, contact and right-hand.armature of relay 207, brush 242, contact 447 (4+13 contact 443 (6), winding of stepping relay 445, armature and contact of relay 466, contact 446' (6), brush 243, conductor 255, upper --right-hand contact 247 r (10), lower. right-hand contact 247 (10+l5), brush 234,

terminal 237, conductor 250, contact 304 (1+4) to ground. Relay 300 becomes energized and closes a circuit from ground through its lett-handarmature and front contact, lower left-hand contact 303 (1), winding of sequence switch magnet 310 to battery and groi'ind. Sequence switch 310 advances out of'position '1 and into position 2. Relay 300 remains energizedin a locking circuit from battery through its righbhand winding and front; contact and inner righthand arn'iature, outer right-hand armature and front. contact of said relay, lower right hand contact 306 (1+4), left-hand contact 305'(1+4), and thence to ground as traced over the fundamental circuit. Relay 300 conipletcs a circuit t'or the updrivc pow-er magnet 317 as followsz'battery, through the winding of said magnet, lower right-hand and upper left-hand contacts 302 (2), front contact and left-hand armature of relay 300 toground. The brush 'snatt 326 is thereby advancedunder the control of the power magnet .317.

' lVhen the stepping. relay 445 energizes in the tundainental (31101110itCOmPleteS acircuit from ground through its armature and 3 contact, upper contact (6), conductor -467,brush 51401 the translator switch, terminal f 25, conductor 529, thence to conductor 453, Fig. 4, armature and back contact of relay 459, winding of relay 460 to battery and ground. Relay 460becon1es en ergized and prepares a locking circuit for itself and relay 459. For each metallic segment of the commutator 314 encountered by the brush 312 a circuit is closed from battery through the right-hand winding, front contactand inner right-hand armature of relay 300', outer right-hand armature and contact. of said relay, lower right-hand contact 306 (1+4),upper right-handcontact 306 (l +2), commutator 314, brush 312 to ground Relay 3001 remains energized in this circuitand the stepping relay is shunted. Consequently the counting relays are energizedqand lockcd'up in sue sion until i'inallythe Zero relays become operated. The fundamental circuit is then opened through the armature and contact of ,relay 466 and acircuit is completed from Sequence switch 440 advances into position 8 and the actuated counting relays are deenergized. a i

As soon, afte r the opening of the fundainentalcircuit at the sender, as brush 312 engages an insulating segment on coinniutator 314, relay 300 releases its arniatures and opens the. circuit of the updrive power magnet. 317; Relay 300 also completes a circuit from ground throughits left-hand armature and "back contact, lower righthand contact 303 (2), winding'of sequence switch magnet 310', to battery'and ground, driving said sequence switch out of position 2 and into position 3. The brush tripping magnet 318 is now .energized in a circuit closed over the lower contact 309 (3+7). Magnet 318 rotates the trip spindle in order to cause the selected set of brushes to be tripped on the next upward movement ofthe brush shaft.

The fundamental circuit is closed once more for controlling the group selecting movement of the office switch and may be traced over the path hereinbefore described with the exception thatthe contacts of sequence switches 310 and 440 are now closed in positions 3 and 8 respectively. Relay 300 becomes energized and completes a circuit from ground through its left-hand armature and front contact, lower left-hand contact 303 3), winding of sequence switch magnet. 310 to battery and ground. Sequence switch 310 becomes energized and moves into position 1. In this position relay 300 remains energized in a locking circuit from battery through its right-hand winding and front contact and inner right-hand armature, outer right-hand armature of said relay, lower right-hand contact 306 (Ll- 1), and thence to ground as described. Relay 300 prepares the operating circuit of the updrive power magnet 317, which includes the lower right-hand and upper left-hand contacts 302 closed in position #1. The brush shaft 326 is driven upwardly in the group selecting movement of the switch.

Upon the energization of'the stepping re.- lay 1&5 in the fundamental circuit, a cir cuit is completed from ground through the armature and contact of said relay, lower contact 6-1 (8), conductor 168, brush 515, terminal 526, conductor 530, thence to conductor e56, Fig. a, winding of the counting relay 154 to battery and ground. Relay a51- becomes energized and prepares circuits for itself and relays 153, and 166. As soon as the brushes 320, 321 and approach the first group of terminals, brush 31,1 engages a metallic segment of commutator 315 and a circuit is closed from battery through the right-hand winding and front contact and inner right-hand armature of relay 300, outer right-hand armature and contact of said relay, lower righthand contact 306 (1+4), upper left-hand contact 306 (3%+et) commutator 315, brush 311 to ground. The closure of this circuit causes the shunt of the stepping relay 445, which permits the energization of counting relays 453 and 166. fundamental circuit while relay 453 completes a circuit including contact 4 11 (8) for driving the sender sequence switch 440 out of position 8.

Shortly after the fundamental circuit is Relay use opens the opened at the sender, the brush 311 engages an insulating position of the commutator segment 315 and relay 300 becomes deenergized. Relay 300 opens the circuit of the upclzrive power magnet 317 and completes a circuit as follows for driving sequence switch 310 out of position 4 and into position battery, through the winding of the magnet of said sequence switch, lower righthand contact 303 1), back contact and left hand armature of relay 300 to ground. 1th sequence switch 310 in position 5 a circuit is immediately closed as follows: battery, through the left-hand winding of relay 300, upper left-hand contact 301 (5+7), upper right-hand contact 301 (5) to ground. Relay 300 becomes energized and closes a circuit from ground through its left-hand armature and front contact, lower left-hand contact 303 (5), winding of sequence switch 310 to battery'and ground. Sequence switch 310 advances into position 6. Relay 300 remains energized in this position provided the first trunk in the selected group, upon the terminals of which the brushes 320, 321 and322 are now standing is engaged. The holding circuit for relay may be followed from battery through the right-hand winding and front contact and inner righthand armature of said relay, outer righthand armature and contact of relay 300, lower right-hand contact 308 (5-1-18), upper right-hand contact 308 (5+6 brush 322 to the grounded test terminal. Relay 300, by remaining energized, completes a circuit for the updrive power magnet 31? including the lower right-hand and the upper left-hand contacts 302 (0). )Vhen the first set of idle terminals is encountered, re-

'lay 300 becomes deenergized and opens the circuit of the power magnet 317, whereby the brushes 320, 321 and 322 are arrested in engagement with said terminals. Relay 300,

on retracting its armatures, completes a circuit from battery through the winding of sequence switch magnet 310, lower righthand contact 3 3 (6), back contact and lefthand armature of relay 300 to ground. Se-

'quence switch 310 advances from position.

6 into position '7. In this position relay 300 is again energized by means of a circuit from battery through the lefthand winding of said relay, upper left-hand contact 301 (5+7), upper right-hand contact 301 (7) to ground. Relay 300 closes a circuit from battery through the winding of sequence switch magnet 310, lower left-hand contact 303 (7,), front contact and left-hand armature of relay 300 to ground, whereby said sequence switch advances from position 7 into position 8. Relay 300 remains energized in position 8 of sequence switch 310 by means of a circuit from battery through the right-hand winding and front contact and inner right-hand armature of said relay,

outer right-hand armature and contact of relayBCtl, lower contact 308'(5+18), lower left-hand contact 308 (7+18), conductor 327, terminal 238, brush 235, upper righthand contact, 222 ("H-1.6), lower right-hand contact 222 (8%+16) to ground.

to select trunk 3,28, 329, the sender sequence switch 140 advances to positions assigned torcontro-lling succeeding switches or other mechanism in accordance with the numerical portion of the designation, as is clearly ex plained in the above'named patent to F. A.

, Stearn and F. J. Scudder 1,395,9TT. When the complete connection has been established, the. sender sequence switch 4. 10 reachessomc position, such as position 1 1, and a circuit is closed from ground through the contact 4418, brush 2 14, upper left-hand contact 214 (10), right-hand winding; of relay 212 to battery and ground. Relay 212 is energized and completes a circuit from battery through the winding of sequence switch magnet 210, left-hand contact 215 (10), front contact and right-hand armature of relay 212, lower contact 213 (i' +16) to Ill) ground. Sequence switch 210 advances from posit on v10 into -POSltlQn '15. As the sequence switch 210 leaves pos tion 11 the upper right-hand contact 209 is opened and the circuit of relay 205 is interrupted. "Re

lay 205, however, remains energized by reason of a substitute circuit closed from battery through its winding, contact and arma} ture of relay 204, right-hand armature and :i'ro-ht contact of relay 205 to gound. Belay 20 1, it will be-noted, becomes energized in serieswlth the calling subscrlbers line over 'a circuit closed by contacts 200 and 201 as the sequence switch 210 reaches position 10% This circuit includes the battery and the left-hand windings of repeating coil 202.

hen tlierlistrict sequence switch 210 leaves position 11 relay'207 becomes de energized and removes the busy condition 'troin the multiple terminals of other sender selector switches to permit this sender to be taken for use in extending subsequent con nections. At the time the-sender sequence switch 41 10 reaches position 1a a condition is created torcausing the release of the translator switch and the numericalregisters. To release the translator switch a circuit is closed from battery through the winding of traced from battery through the winding of the stepping magnet 116, armature and con tact of said magnet, conductor 41:77, brush 411','contact 4:38 to ground. Magnet 416 interrupts its own circuit and advances the brushes oi the control switch until they reach their tenth position terminals, at

which time brush 411 opens the stepping Atter the oliice switch has been'positioned circuit of said magnet. In, position 1.0 of the control switch a circuit is established. from ground through the brush. 11 1, ter- "minal 1 78, conductor 119, thence through the brushes 5 12.

5 17, and 557 and the contacts antlarl'natures and windings ot the respective stei'iping magnets 5411, 546,551 and 556 of the numerical registers to battery and ground. The numerical registers are thereby restoredto their norn'ial position at which tieni a series circuit is completed from ground through the brushes .558, 553, 548 and 543 in series, terminal 437, brush 115, contact and armature and winding of stepping magnet 116 tobattery and ground. Magnet 110 restores the controlswitch to its normal position. lVhen the control switch reaches its normal position a circuit is closed from battery through the winding of Sequenceswitch magriets'rsl-O, lefthand con tact 439 (-10-l-18), terminal 479, brush 411. contact. 138 to ground. Sequence switch a lthereupon is restored to its normal position 1.

lVhen the district sequence switch 210 leaves position 10 the calling subscribers line is disconnected at contaets'200 and 201 from the impulse circuit leading to the im pulse relay at the register sender. Relay 100 thereupon becomes deenergized and after a sutticient interval of time the SlOWtO*1(3 leaserelay 104 retracts its armature, pro

vided the sender sequence switch 4 is already restored to normal. as explained, a circuit is now completed from ground through the armature and back contact oi? relay 100, righthand armature of relay 104-, brush 411,t-er.minal 79,, contact 4512 (1). upper right-hen d contart 4.08 (sl+18) wind ing of sequence switch nmgnet 410 tobat tery and'g round. The class sequence switch 410 is thereby driven from position 10 into its normal position 1. v

lVith' the district sequence switch 21.0 in posit-ion and the slice sequence switch 310 in position, 8 a coi'iversational circuit is established through to the trunlc328, 2329. V hen the calling subscriber later hangs up his receiver the circuitof relay 201 is opened. Relay 1 in turn severe the holding circuit of relay 205 and this relay becomes deenergized. Relay 205, completes a circuit from ground through its right-hand normal contact, righthand. contact 21.) (12+17), left-hand contact 219 (12+17), winding of sequence switch magnet 210 to batteryand ground. Sequence switch 210 moves from position 15 into position 18. The district selector switch is restored to ill ' contact 2 is opened and the hereinbeiiore traced circuit of relay 300 is interrupted. Relay 300 releases its armatures and completes a circuit from battery through the winding of sequence switch magnet 310, lower right-hand contact 303 (8-1-17), back contact and left-hand armature of relay 300 toground. Sequence switch 310 leaves position 8 and moves into position 18. In this position the office selector switch is restored to its normal position by the down drive power magnet 319. The circuit for magnet 2310 may be traced from batt i'y through the winding thereof, lower left-hand and upper right-hand contacts 301 18) to ground. YJhen the switch shaft 320 is in its normal position sequence switch 310 is driven out of position 18 and into position 1 by means of a circuit from battery through the winding of the power magnet of said sequence switch, upper right-hand contact 303 (3+18), segment 313, brush 312 to ground. At the time relay 205 becomes deenergized it opens at its left-hand armature and contact the circuit which up to this time has been holding the relays 206 and 1 actuated. Relay 10 1-, on deenergizing, completes a circuit as follows for restoring the individual line switch to its normal position: battery, through the winding and armature and contact of stepping magnet 105, lowermost armature and contact of relay 10 1. right-hand armature and back contact of relay 10S, brush 107, segment- 112 to ground. The stepping magnet 105 interrupts its own circuit and restores the brushes 106, 107, 108., etc. to their normal position where the brush 10'? disengages segn'ient 112 and severs the operating circuit of said stepping magnet.

Tho circuits of the system disclosed herein are arranged to cause the registration of a certain code in response to the transmission of a single series of impulses from the subscribers station. For example, if a called subscriber wishes to converse with an operator it is desirable that only one digit be dialled, such as the digit 0. As will presently, be explained, when the subscriber dials the digit 0 to permit a series of ten impulses, the translator switch is caused to step its brushes to the tenth I the row level and then to automatically rotate said brushes to the first set of t ninals in this level. Referring particularly to Fig. 5, assume that the brushes 511, 512, 513, 51 1, etc., have been advanced opposite the tenth level of terminals in their res ective sections responsive to the transmission of a series of ten impulses. At this time the auxiliary brush 518 is engaging the tenth terminal 519 in its armatures following the denergization of the slow to release relay 105, a circuit is hrst st p of the rotary magnet 502 rotates the brush out oi c agement with ternii- "181111 of brush 518 519 opens the circuit oi magnd the switch comes to rest. As

he disen with ternnnal net 503 a above explained, the class sequence switch I no leaves position 3 and connnences to rotate following the setting of the translator switch. Relay e71 in this case becomes energized when sequence switch 410 reaches posi tion 11. The circuit for relay 471 may be traced from the winding of said relay, upper left-hand contact 4. 72 (14:), contact and outer right hand armature of relay 501, terminal 521, brush 511 to ground. Since thetranslator switch is standing on the first terminals in the tenth level, it will determine, according to the manner in which these terminals are wired to the counting relays, the operation of the district and oliice switches in such a manner as to select a. trunl; line leading to the operators position (not shown). The release of the apparatus takes place in exa tly the same manner as hereinbetore described.

li hat is claimed is:

1. In a telephone system, a telephone line, an automatic switch having a plurality of line extending positions for extending said line, a selective switch having a plurality of differing directed movements, means for transmitting successive series of impulses over said line to said selective switch, neans responsive to said impulses for operating said selective switch, and means operated in accordance with the position taken by the selective switch for directively controlling the positioning of said automatic switch.

2. In a telephone system, a. telephone line, a plurality of selectively operable automatic switches having a plurality or" line extend- As soon as relay 500 releases successive series of impulses over said line to said selective switch, means responsive to said impulses for operating said selective switch, andmeans operated in accordance with the position taken by the selective switch for directively controlling the positioning of said automatic switches.

In a telephone system, a subscribers line, automatic switches having a plurality of line extending positions for extending said line, aselective switch having a plurality of difi ering directed movements, means at the subscribers substation for transmitting successive series. of impulses over said line to said selective switch, means responsive" to said impulses for operating said selective switch, and means operated in accordanc'ewith the 'i'ositiontaken by the selective switch for directively controlling the positioning of said automatic switches.

4.. In a telephone system, a subscribers line, automatic switches having a plurality of line extending positions for extending saldline, a selective switch having a'plurality of differing directed movements, means for transmitting series of impulses over said line to said selective switch, means responsive to each of said series oi impulses for operating said selective switch in one of its movements, and means operated in accordance with the position taken by the selective switch for directively controlling the positioning of said automatic switches.

In a telephone system, a subscribers line, automatic switches having a plurality of line extending positions for extending said line, a selective switch having a pluralityot ditlering directed movements, a sender at the subscribers substation for transmitting series of impulses over said line to said selective switch, means responsive to each 01. said series of impulses for variably operating said selective switch in its different movements, and means operated in accordance with the position taken by the selective switch for directively controlling the positioning of said automatic switch.

6. In a telephone system, a telephoneline, automatic switches for extending said line, a unitary selective switch having a plurality of separate directed movements, means for transmitting impulses over said line to. said selective switch, means'responsive to said impulses for variably positioning said selective switch, and a variably operable sending mechanism operated in accordance with the position taken by'said selective switcliefor controlling the operation of said automatic switches. i?

7. In a telephone system, a telep'honeline, an automatic switch for extending said he,

. a unitary selective switch having a plurality of separate directed movements, means for transmitting impulses over said line to said selective switch, means responsive to said impulses for variably positioning said selective switch, a sending mechanism inrluding a series of counting relays, means for operating a variable number of said countingrelays depending upon the position taken by said selective switch, and means controlled bysaid counting relays for operating said automatic switches.

8. In a telephone system, a telephone line, automatic switches having a plurality of line extending positions for extendingsaid line, a selective switch having a'plurality of differing directed movements, an impulse circuit including said telephone line, means for extending said impulse circuit to said selective switch, means for transmitting sue- 'cessive series of impulses overv said circuit, means responsive to said impulses for operating said selective switch, and means dependent upon the position taken by said selective switch for directively controlling the positioning of said automatic switches.

' 9. In a telephone system, a telephone line,

automatic switches having a plurality of line extendingpositions for extending said trolling the positioning of said automatic switches.

10. In a telephone system, line, automatic switches having aplurality of line extending positions for extending said line, a selective switch having twodiffering directed movements, means for trans- 'mitting successive series of impulses oversaid line to said selective switch, means responsive to said impulses for operating said selective switch, and means operated in accordance with the position taken by the se lective switch for directively controlling the positioning of said automatic switches.

11. In a telephone system, a telephone line, automatic switches having a plurality of line extending positions for extending said line, a selective switch having a plurality of step-by-step movements, means for transmitting impulses over said line to said selective switch, means responsive to said impulses for variably operatingssaid selective switclnanol means operatedin accordance with the position taken by l switch for directively controlli tioning of said automatic swit es.

a telephone 

